Means for indicating the height of a liquid in a tank



y 12, 1932- w. P. DALRYMPLE 1,866,843

MEANS FOR INDICATING THE HEIGHT OF A LIQUID IN A TANK Filed Jan. 6, 1923)lIll/IlIIllIlIlIIIlIIIlIIII/II Patented july 12, 1932 NITED STATESPATENT OFFICE "WILLIAM P. DALRYMPLE, OF CHICAGO, ILLINOIS, ASSIGNOR TOBENDIX STROMBERG i J: CARBURETORCOMPANY, OF CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS MEANS FOR INDICATING THE HEIGHT OF A LIQUID IN ATANK Application filed January 6, 1923.

This invention relates to improved means for indicating the height of abody of liquid in a tank from which a supply is being drawn forconsumption, as for example in connection with the gasoline tank carriedby an auto mobile. Ithasparticularly to do with improvements adapted foruse in connection with such apparatus as make use of a vacuum system forintermittently drawing up a quantity of the liquid fuel from a supplytank for transference to a carburetor. The object of the invention is toprovide improved means, controlled by the action 'of such'vacuum systemin intermittently creating and destroying a vacuum in the usual vacuumchamber, to indicate on a suitable pressure gauge the height of theliquid in the supply tank. I accomplish this object by the means shownin the drawing and hereinafter particularly described, and while theconstruction shown is well adapted for the carrying out of'my inventionit is to be understood that]: do not intend to herein be restricted tosuch an embodiment, as the details of construction and arrangement ofthe several parts may be varied in many particulars. What I believe tobe new will be set forth in the claims.

In the drawing the figure, which is largely diagrammatic, shows myinvention in connection with a well-known form ofintermittently-operating vacuum-creating apparatus that isemployed inconnection with the feeding of gasoline to the carburetor of anautomobile engine, most of the parts being shown in section and somearts being broken away.

In said draw1ng5 and 6 indicate,- respectively, the outer and innerchambers of a well-known type of vacuum fuel feed system designed forautomobile use, there being in the head 7 that hermetically closes theupper ends of both such chambers the usual passage 8 through whichgasoline is admitted to the interior of the chamber 6, the passage 9through which air, from the inner chamber 6 is exhausted and the passage10 open to the atmosphere. The passage 8 has heretofore been connectedwith a pipe that led directly to the interior of the supply tank Abut,as here shown in connection with my improvements, there is substitutedfor such direct- Serial No. 611,002.

which vacuum or suction is also established in the inner chamber 6 thatis connected with the manifold by the pipe 11. The usual pipe for theadmission of atmospheric pressure to the inner chamber 6 through thepassage 10 is shown at 13. The passages or ports 9 and 10 are controlledby the usual valves that respectively move upwardly and downwardly toseating or closing positions, which valves are operated by means oflever and spring devices that are interposed between such valves and theusual float 14. At the lower end of the inner chamber 6 is the ordinarynozzle 15 through which the gasoline may flow into the outer chamber 5,the nozzle being provided with a check valve 16 that will be held closedwhen the vacuum exists in the inner chamber. A pipe 17 connects thechamber 5 with the carburetor 18 as usual. The construction andarrangement of all the parts so far briefly described, and referred toby reference numerals, is so well understood that I do not deem itnecessary to more particularly describe them. Furthermore, my inventionis not limited to employment in connection with the particularvacuumproducing means shown but may be advantageously used with otherforms of such apparatus that will intermittently produce a vacuum in achamber so that the liquid fuel from a supply tank is thereby caused tobe drawn into it and fed therefrom.

Turning now to the means connected with a suitable vacuum-producingagency, and with which my invention is particularly concerned, theconduit which connects the vacuum chamber with the supply tank A andthrough which the liquid is drawn intermittently by the suction producedtherein by reason ofthe production of the vacuum, is constituted ashereshown of a plurality of pipe sections and a plurality of receptaclesinto which receptacles the open ends of the pipe sections extend. One ofsuch pipe sections has been heretofore referred toviz., the pipe at thatis secured to the head 7 of the vacuum chambers and communicates withthe passage 8 therein. The upper end portion of this pipe at extendsthrough a wall of a closed receptacle 6 with its open upper endpositioned near the upper wall of such receptacle. Another pipe sectionis indicated by 0. Its upper end portion projects into the receptacle 6with its open upper end also positioned near the upper wall of thereceptacle. Through the portion within the receptacle but close to thebottom wall of the receptacle this pipe section 6 is provided with oneor more openings (1, each of which is preferably quite a small one, asindicated, and the object of which will be hereinafter described. Thispipe section 0 has its lower end portion projecting into a second closedreceptacle or pressure chamber 6 with its open lower end, in theconstruction shown, close to the bottom of said receptacle. From theupper part of this receptacle 6 leads another pipe section f that passesinto the supply tank A and has its open lower end closely adjacent tothe bottom of the tank. From the drawing it will be seen that the parts0, e and 7 together constitute a conduit through which liquid from thetank A will be drawn by suction into the receptacle 6, the pipe a, andthe chamber 6 whenever a vacuum is created in the usual manner in suchchamber, the conduit parts a, e, and f, the pipe at and the receptacletogether comprising a complete conduit means through which liquid flowsfrom the supply tank to the vacuumtank during the normal feedingoperation of the latter.

Communicating with the upper portion of the receptacle 6 is a pipe 9whose other end communicates, in the construction shown, with anindicator comprising a chamber k in the upper portion of a casing h,said casing having a lower chamberh adapted to contain a suitable heavyliquid such as is commonly used in indicating devices of the manometertype. Thechamber k communicates with a sight tube h so that theliquidmay flow freely back and forth according to the pressure exerted uponit, the upper end of the sighttube having an opening for the passage ofatmospheric air as usual. A float It in the chamber 7L2 controls a valvek adapted to close an opening in a wall 72, that divides the casing itinto the two chambers mentioned. Any other type of indicating deviceadapted to be afllected by air pressures, as for example those employinga yielding diaphragm maybe substituted, if desired, for the type ofindicator here shown and briefly described.

lVith a vacuum-creating mechanism pro videdwith a conduit substantiallyas shown and described interposed between it and the supply tank andhaving connected with such conduit at a point between its two members 0and f a suitable indicating member that will be sensitive to variationsin the air pressure in the conduit, the operation will be as follows:When a' vacuum is created in the chamber 6 the air will necessarily beexhausted from the conduit and liquid from the tank A will be drawn uptherethrough to and into said chamber 6. After the vacuum has beendestroyed by reason of the movement of the float 14 that causes theclosing of the valve that controls the passage 9 and the opening of thevalve that controls the passage 10, in the usual manner, the liquid thatis in the pipe section f will flow back into the tank A, and the liquidin pipe section 0 will flow down into the receptacle 6 and be theretrapped or retained. B reason of the suction induced by the down ow ofliquid in the pipe sections 0 and fatmospheric air will be drawn fromthe vacuum chamber 6 and will then pass through the pipe a, receptacle 6and down through the pipe 0 and up through the liquid in the'receptaclee where it is trapped and into both the conduit pipe section f and thepipe 1 that communicate with the indicator. The liquid that has beentrapped in the uppermost receptacle 6 will slowly escape therefromthrough the opening or openings cl and pass down the pipe section 0. Therecessional flow of liquid in pipes f and 0 draws air through pipe a,chamber 1), pipe 0 and chamber a into pipe 7. Pipe 0 merely empties itsliquid into chamber e. The subsequent flow of liquid from chamber 6through small hole d in pipe 0 does two things, namely, it causes air tobe entrained with liquid flowing down said tube 0 into chamber 0 whereit is disentrained and it causes the level of liquid in said chamber eto be raised, thereby compressing whatever air is contained therein andwhatever air is released thereinto by the mixture of liquid and airflowing down said tube 0 into chamber e. The admission of this liquid tothe pipe section 0 establishes a head therein which operates to increasethe air pressure in the receptacle 6 and'pipe sections f and gcorresponding with the hydrostatic pressure at the lower end of the plpe7 which, as has been explained, is adjacent to the bottom of the tank A.Obviously, the air pressure cannot go beyond that point as any excesspressure would cause the air to pass down through the pipe f and escapeinto the tank A. This air pressure is transmitted through pipe section 9to the chamber h at the upper end of the casing 71., and is applied tothe upper surface of the liquid in the chamber A thereof so that by theextent tov which the liquid in the indicator rises in the sight tube hthereof the observer will be apprised of the height of the liquid in thesupply tank. Of course a corresponding indication would be effected by-such air pressure when exerted upon a mechanical movable member inother typesfof indicating devices, as will be understood.

'When'the charge ofgasoline that has been drawn into the vacuum chamberhas been discharged therefrom thelvacuum will again be reestablished inthe usual manner through the movement of the float 14 and another chargedrawn up through the described conduit by suction and fed into thechamber 6, as already described. Asthis filling operation takes placethe air is also exhausted, of course, from the pipe 9 and the chamber kin the indicator casing, with the result that the column of liquid inthe sight-tube it falls underthe influence of the atmospheric pressureas air is admitted through the hole in the upper end of such tube. Theexhaustion of air from pipe 9 raises the liq uid level in the lowerchamber b so that the float h causes the valve h to close the opening inthe wall it. Thus the entire suction of the vacuum apparatus isavailable to draw liquid from the tank A and none'is lost through theindicating gauge. The result is, therefore, that the indicator is thennon-effective for showing the height of the contents of the supply tankduring the time that the chamber 6 of the vacuum apparatus is filled orbeing filled with liquid. This failure to indicate is of littleimportance though, because at all othertimes the indicator will properlyfunction, and as suchother times occur frequently and continue for avery appreciable length of time depending of course upon how fast theengine is running and the gasoline is being consumedthe observer hasample opportunity for determining from the indicator as to the height'ofthe gasoline inhis supply tank.

Unlike other devices that have employed air pressure means in connectionwith the fuel-supply tank and an indicator or gauge my invention doesnot require the use of manually-operated means for replenishing theair-supply, but, as will be understood from the description hereinabovegiven, the air to be held under ressure between the supply tank and thein icating mechanism is always supplied automatically, which is, ofcourse, a great advantage. Furthermore, such prior devices have beenobjectionable in that they have required separate connections with thesupply tank, whereas with my invention no special fitting or connectionis re- 5 quired to be made to the supply tank inasmuch as the oneconduit that is required for connecting the tank and the vacuum chamberserves also as the air-conducting and confining means.

While my invention has been designed for use particularly in connectionwith automobiles, it may be advantageously employed in other situationswhere a vacuum-producing apparatus is employed for intermittently 35ralsing liquid from a tank and Where an indicator or gauge is desirablefor showing the height of the liquid in the receptacle from which thesupplyis being drawn.

What I claim as my invention and desire to secure by Letters Patent, isal.'In an apparatus ofthe class described, the combination with a supplytank, of a receptacle at a higher lever than said tank, a vacuum chambercommunicating with the upper portion of said receptacle, means forintermittently creating a vacuum in said chamber, a conduit forconducting liquid from said tank to said chamber under the influence ofsuction, said conduit comprising an air pressure chamber, a pipeconnecting the upper portion of said pressure chamber with the lowerportion of said tank, and a pipe connecting the lower portion of saidpressure chamber with the upper portion of said receptacle, and adraining connectionbetween the lower portion 'of said receptacle and thelatter pipe, whereby recessional flow of liquid through said conduitwill entrain and conduct air to said pressure chamber to establish ahydrostatic pressure in said pressure chamber corresponding with thehydrostatic pressure at theibottom ofsaid tank, an air a pressurecontrolled indicator and means whereby said indicator is connected withsaid pressure chamber.

2. In an apparatus of theclass' described, the combination with a supplytank, of a receptacle at a higher level than said tank, meanscommunicating with the upper portion of said receptacle forintermittently creating a vacuum therein, a conduit for conductingliquid from said tank to said receptacle under the influence of suction,said conduit C0111? prising a pressure'chamber above the supply tank, apipe communicating with the lower portion of said tank and with theupper portion of said pressure chamber, and a pipe com-- municating withthe lower portion of'said pressure chamber and having portscommunicating with the upper and lower portionsof said receptacle, apressure responsive indicator, and means whereby said indicator isconnected with said pressure chamber; at a point above'said lower ports.

3. In an apparatus of the class described,

thecombinatio'n' with a sup ly tank, of-a receptacle at a higher level tan said tank-,"a vacuumchamber connected with the upper portion of saidreceptacle, means for intermittently creating a vacuum in said chamber,conduit. means connected with the upper portion of said receptacle andwith the lower portion of said tank for conducting liquid from said tankto said chamber "under-the influence of suction, said-conduit meanscomprising means for causing the recessional flow of liquid from saidvacuum chamber to said supply tank to entrain airin said conduit .to apressureicorresponding substan:

tially with the hydrostaticpressure at the bot tom of said tank, meansabove the supply tank to trap said entrained air, an indicator, andmeans wherebysaidindicator is controlled by the air pressure injsaidconduit means whereby said indicator'is adapted to indicate the head ofliquid in thezsupply tankand the-operation ofth'e vacuum creating meansin drawing liquid from the supply tank to said vacuum chamber; v a 1' I4. In combination, a main tank, a chamber providing an air trap, conduitmeans placing'said air .trap in commmunication with the liquid ofthe'tank at the-depth to be measured, said chamber lying above theybottom of said tank, a suction .pipe communicating with the liquid in.the tank. through said chamber and conduit means, means fordrawingliqui'd in .said pipe to apoint above the level of liquid in thetank and permitting it to recede to the tank, and means cooperating withsaid suction pipe for introducing air into said receding column, saidsuction pipe and said conduit means opening into said air trap so as toretain some of the entrained air in said trap.

- -5. In combination, a main supply tank, an air trap, means placing.the upper portion of the air trap in communication with the lower partof the main tank, said airtrap lying above the liquid in the supplytank, a pressureactuated indicator connected to the air spaceof thetrap, a liquid trap above the air trap, a vacuum tank and meansconnecting the same to the top of the li'quidtrap, a connection from theliquid trap to the'bottom of the air trap, an'dmeans for discharging airinto said connection and thereby into the air space of the air trapbythe falling column of liquid from the liquid trap to the air trap.

6. In combination, a tank for liquid, conduit means including a conduitextending downwardly "to a point adjacent the bottom draining connectionwith the lower portion :ofvsaidreceptacle, an indicator, and meanswhereby said indicator is controlled by the pressure insaid pressurechamber.

8. The method of indicating the quantity of liquid in a tank, whichcomprises raising a vcolumn of liquid .by suction from the lower portionof the tank, permitting said column of liquid to fall, introducing airinto one portion of'said column while the same is moving, separating outtheair at substantially atmospheric pressure and trapping the same,increasing the pressure of said trapped air by subjecting it to thehydrostatichead of a portion of said column of liquid until the pressureis equal to the hydrostatic head of the liquid in the tank, andmeasuring the pressure of said trapped air.

9. The method of indicating the quantity of liquid in a tank, whichcomprises raising a column of liquid by suction from the lower portionof the tank, permitting said column of liquid to fall, introducing airinto said column while the same is falling, separating out the air'fromeach air-containing portion of'said liquid column during theretrograde movement of that portion toward the tank, trapping the air soseparated, increasing the pressure. of said trapped air by subjecting itto the hydrostatic head of at least a part of said column-of liquiduntil the pressure is equal to the hydrostatic head of the liquid in the:tank, and-measuring the pressure of said trapped air; i

" WILLIAM P. DALRYMPLE.

of the tank and having an o en communication'with the liquid at saidpoint, an air trap communicating above the bottom thereof with saidconduit ata point above the lower end of the latter, a suction pipeextending from a point near the bottom of the trap to a point above thetrap, and'a chamber having a suction-connection to the top thereof, saidsuction pipe at its'upper end having commu-.

the combination with a supply tank, of a receptacle at a higher levelthan said "tank, a vacuum tank, means whereby said vacuum tank isconnected to the upper portion of said receptacle, for intermittentlycreating a vacuum in said receptacle, an air pressure chamber' at alower level than said receptacle, 1 7 means conneotingthe upper portionof, said

